1、Designation: F 799 06Standard Specification forCobalt-28Chromium-6Molybdenum Alloy Forgings forSurgical Implants (UNS R31537, R31538, R31539)1This standard is issued under the fixed designation F 799; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers requirements of cobalt-28chromium-6molybdenum alloy (UNS R31
3、537, R31538,R31539) high-strength forgings for the manufacture of surgicalimplants. The properties specified in this document specificallyapply to finished or semifinished parts that receive no subse-quent thermomechanical processing.1.2 The values stated in inch-pound units are to be regardedas sta
4、ndard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 Wrought material to be used as forging stock in themanufacture of forgings conforming to this specification,typically hot worked and unannealed wit
5、h a surface finishsuitable for forging, shall be fabricated and supplied inaccordance with F 1537.2. Referenced Documents2.1 ASTM Standards:2E8 Test Methods for Tension Testing of Metallic MaterialsE18 Test Methods for Rockwell Hardness and RockwellSuperficial Hardness of Metallic MaterialsE29 Pract
6、ice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE112 Test Methods for Determining Average Grain SizeE 165 Test Method for Liquid Penetrant ExaminationE 930 Test Methods for Estimating the Largest Grain Ob-served in a Metallographic Section (ALA Grain Size)F75
7、 Specification for Cobalt-28 Chromium-6 MolybdenumAlloy Castings and Casting Alloy for Surgical Implants(UNS R30075)F 601 Practice for Fluorescent Penetrant Inspection of Me-tallic Surgical ImplantsF 981 Practice for Assessment of Compatibility of Bioma-terials for Surgical Implants with Respect to
8、Effect ofMaterials on Muscle and BoneF 1537 Specification for Wrought Cobalt-28 Chromium-6Molybdenum Alloy for Surgical Implants2.2 ISO Standards:3ISO 6892 Metallic MaterialsTensile Testing at AmbientTemperatureISO 9001 Quality Management SystemsRequirements2.3 American Society for Quality Standard:
9、4ASQ C1 Specification of General Requirements for a Qual-ity Program3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 lot, nthe total number of forgings produced from thesame heat of starting material under the same conditions atessentially the same time.4. Ordering Information4
10、.1 Inquiries and orders for material under this specificationshall include the following information:4.1.1 Quantity, number of pieces4.1.2 ASTM designation, date of issue, and alloy number,4.1.3 Condition,4.1.4 Mechanical properties,4.1.5 Finish,4.1.6 Applicable dimensions or drawing number,4.1.7 Sp
11、ecial tests, if any, and4.1.8 Other requirements.5. Materials and Manufacture5.1 Materials for forgings shall be bar, rod, or wire fabri-cated in accordance with Specification F 1537.5.2 The material shall be forged by hammering, pressing,rolling, extruding, or upsetting, and shall be processed, ifp
12、ractical, so as to cause metal flow during the hot-workingoperation to be in the most favorable direction for resistingstresses encountered in service, as may be indicated to thesupplier by the purchaser.1This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Mater
13、ials and Devices and is the direct responsibility ofSubcommittee F04.12 on Metallurgical Materials.Current edition approved Oct. 1, 2006. Published October 2006. Originallyapproved in 1982. Last previous edition approved in 2002 as F 799 02.2For referenced ASTM standards, visit the ASTM website, www
14、.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.an
15、si.org.4Available from American Society for Quality (ASQ), 600 N. Plankinton Ave.,Milwaukee, WI 53203, http:/www.asq.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
16、s.5.3 Forgings shall be free of splits, scale, cracks, flaws, andother imperfections not consistent with good commercialpractice (see Note 1). Offset or mismatch allowance, dependentupon part size and configuration, shall be within standardforging tolerances.5.4 Optional indentification marks, inclu
17、ding the purchas-ers logo, material designation, heat code number, and impres-sion number, may be placed upon each forging, the method andlocation of which shall be as specified by the purchaser.NOTE 1Compliance to these requirements may be verified by TestMethod E 165 or Practice F 601 or other sui
18、table methods.6. Chemical Requirements6.1 The cobalt-28chromium-6molybdenum alloy forgingsshall conform to the chemical requirements prescribed inTable 1 of Specification F 1537. The supplier shall not shipmaterial that is outside the limits specified in Table 1 ofSpecification F 1537 for the applic
19、able alloys. Specification F1537 contains three alloys:Alloy 1 Low Carbon (UNS R31537)Alloy 2 High Carbon (UNS R31538)Alloy 3 Dispersion Strengthened (UNS R31539)7. Mechanical Requirements7.1 Tensile Properties:7.1.1 Tensile properties shall be determined in accordancewith Test Methods E8.7.1.2 The
20、mechanical properties of test specimens preparedfrom finished or semifinished parts shall conform to therequirements in Table 1.7.1.3 Tension test specimens shall be produced from fin-ished or semifinished parts or from material having the sameprocess history as that which exists in the final forgin
21、g. Tensionspecimens may have a ground finish on the reduced section andmay be taken in a direction parallel to the long axis of thefinished or semifinished part.7.1.4 A minimum of two tension test specimens shall betested. Should either of the two specimens not meet thespecified requirements, two ad
22、ditional specimens shall betested and both must pass.7.1.5 If any fracture takes place outside the middle half ofthe gauge length or in a punched or scribed gauge mark withinthe reduced section, the elongation value obtained may not berepresentative of the material. In acceptance testing, if theelon
23、gation so measured meets the minimum requirementsspecified, no further testing is required, but if the elongation isless than the minimum requirements, discard the test and retest.7.1.6 In some instances, mechanical test pieces may not beobtainable directly from forged parts due to their configurati
24、onor small size. Instead of mechanical testing, these parts shallexhibit hardness of HRC 35 to 45 when tested in accordancewith Test Methods E18.7.2 HardnessForgings conforming to this specificationshall have a minimum Rockwell C hardness of 35 HRC. Thehardness determination shall be performed in ac
25、cordance withTest Methods E18.8. Special Tests8.1 The average grain size of forgings shall be ASTM No. 5or finer when tested in accordance with Test Methods E112.Inforgings it may not be possible to fully recrystallize the entiremicrostructure to a fine grain size. Duplex microstructuresexhibiting a
26、reas of unrecrystallized grains as large as ASTMNo. 2 (or ALA No. 2, as applicable, see Test Method E 930)shall be acceptable provided a minimum of 50 % of the area ofeach section examined displays an average grain size ofASTMNo. 5 or finer; and the average microhardness of the largergrained regions
27、 is the equivalent of HRC 38 or greater. Inquantities of 10 % (by area of the metallographic section inquestion) or less, unrecrystallized grains as large asASTM No.0 (or ALA No. 0, as applicable) shall be acceptable providedthe average microhardness of the larger grained regions is theequivalent of
28、 HRC 40 or greater.8.2 When specified by the purchaser, fluorescent penetrantinspection shall be performed on forgings. These penetrantinspections shall be performed in accordance with PracticesE 165 and F 601.9. Significance of Numerical Limits9.1 The following applies to all specified limits in th
29、isspecification. To determine conformance to these limits, anobserved calculated value shall be rounded to the nearest unitin the last right hand digit used in expressing the specificationlimit, in accordance with the rounding method of Practice E29.10. Certification10.1 The supplier shall provide a
30、 certification of conform-ance that the material was tested in accordance with thisspecification and met all requirements. A report of the testresults shall be furnished to the purchaser at the time ofshipment.11. Quality Program Requirements11.1 The alloy suppliers and any processors shall maintain
31、 aquality program as defined in ASQ C1 or ISO 9001.12. Keywords12.1 cobalt alloys; cobalt alloys (for surgical implants);cobalt-chromium-molybdenum; forgings; metals (for surgicalimplants)TABLE 1 Mechanical RequirementsUltimate TensileStrength, min,psi, (MPa)Yield Strength(0.2 % offset),min, psi (MP
32、a)Elongation,Ain 2 in. or4D or 4W, min %Reduction inArea, min, %Hardness,HRC, min170 000 (1172) 120 000 (827) 12 12 35AElongation of material 0.063 in. (1.6 mm) or greater in diameter (D) or width (W) shall be measured using a gauge length of 2 in. or 4D or 4W. The gauge length mustbe reported with
33、the test results. The method for determining elongation of material under 0.063 in. (1.6 mm) in diameter or thickness may be negotiated. Alternately, agauge length corresponding to ISO 6892 may be used when agreed upon between supplier and purchaser. (5.65 sqaure root So, where So is the original cr
34、oss sectionalarea.)F799062APPENDIXES(Nonmandatory Information)X1. RATIONALEX1.1 The purpose for this specification is to characterizecomposition and properties to assure consistency in thermo-mechanically processed cobalt-28chromium-6molybdenumforgings used in the manufacturing of medical devices th
35、atreceive no subsequent metallurgical processing.X1.2 Published data5,6indicate that material with a fine-grained homogeneous metallurgical structure resulting fromforging will be superior with respect to tensile strength andfatigue resistance compared to material conforming to Speci-fication F75. B
36、ased upon this, requirements include fine-grained microstructure and high tensile strength.X1.3 Some complex metallic phases, such as carbides,oxides, or carbonitrides, or combinations thereof, may bepresent in the microstructure of this alloy.X1.4 ISO standards are listed for reference only. Althou
37、ghthe ISO standards listed in Section 2 are similar to thecorrespondingASTM standards, they may not be identical. Useof an ISO standard in addition to or instead of a preferredASTM standard may be negotiated between the purchaser andsupplier.X2. BIOCOMPATIBILITYX2.1 The alloy composition covered by
38、this specificationhas been successfully employed in human implants for over adecade. This material has been found to produce a well-characterized level of local biological response when tested inaccordance with Practice F 981 or equivalent.X2.2 The material composition conforming to this specifi-cat
39、ion has been evaluated for biocompatibility and corrosionresistance and has been found to be comparable to materialconforming to Specification F75.X2.3 No known surgical implant material has ever beenshown to be completely free of adverse reactions in the humanbody; however, long-term clinical exper
40、ience has shown anacceptable level of biological response can be expected, if thismaterial is used in appropriate applications.SUMMARY OF CHANGESCommitte F04 has identified the location of selected changes to this standard since the last issue (F 799 02)that may impact the use of this standard. (App
41、roved Oct. 1, 2006.)(1) Added Section 3, Terminology.(2) Added Section 9, Significance of Numerical Limits, andadded Practice E29to Referenced Documents.(3) Added ISO 9001 to Referenced Documents and to Section11.(4) Deleted X1.3 because chemical composition notes in thissection are in the associate
42、d material specifications.(5) Wording and numbering was revised in many areas toupdate the specification (editorial changes).ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are ex
43、pressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revi
44、sed, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you ma
45、y attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United Sta
46、tes. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).5Bardos, D. I., “High Strength Co-Cr-Mo Alloy for Prostheses,” CurrentConcepts of Internal Fixation of Fractures, edited by H. Uhthoff, Springer Verlag,New York, NY, 1980, p 111.6Weisman, S., “Vitallium FHS Forged High-Strength Alloy,” Current Conceptsof Internal Fixation of Fractures,p118.F799063
